LogFAQs > #939545197

It's a statistical impossibility that there have not been, are not, or will never be other sentient aliens, to say nothing of non-sentient alien life(there's growing evidence of multiple instances of that having existed or currently existing in our own solar system).
However, given the vast scale of existence versus the relatively short existences of civilizations(and the relatively tiny impact area of our sample size: us) and our understanding of the laws of physics, it's highly unlikely we will ever meaningfully interact with another sentient race. We would be incredibly fortunate to even ever conclusively prove one had existed in the past.